EP0350061A2 - Amortisseur de chocs à force d'amortissement réglable - Google Patents

Amortisseur de chocs à force d'amortissement réglable Download PDF

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Publication number
EP0350061A2
EP0350061A2 EP89112472A EP89112472A EP0350061A2 EP 0350061 A2 EP0350061 A2 EP 0350061A2 EP 89112472 A EP89112472 A EP 89112472A EP 89112472 A EP89112472 A EP 89112472A EP 0350061 A2 EP0350061 A2 EP 0350061A2
Authority
EP
European Patent Office
Prior art keywords
fluid passage
valve body
valve
fluid
shock absorber
Prior art date
Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
Granted
Application number
EP89112472A
Other languages
German (de)
English (en)
Other versions
EP0350061A3 (fr
EP0350061B1 (fr
Inventor
Toshiki Kobayashi
Toshinobu Ishida
Yasumasa Hagiwara
Masayuki Yano
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
Denso Corp
Original Assignee
NipponDenso Co Ltd
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Filing date
Publication date
Application filed by NipponDenso Co Ltd filed Critical NipponDenso Co Ltd
Publication of EP0350061A2 publication Critical patent/EP0350061A2/fr
Publication of EP0350061A3 publication Critical patent/EP0350061A3/fr
Application granted granted Critical
Publication of EP0350061B1 publication Critical patent/EP0350061B1/fr
Anticipated expiration legal-status Critical
Expired - Lifetime legal-status Critical Current

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Classifications

    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F16—ENGINEERING ELEMENTS AND UNITS; GENERAL MEASURES FOR PRODUCING AND MAINTAINING EFFECTIVE FUNCTIONING OF MACHINES OR INSTALLATIONS; THERMAL INSULATION IN GENERAL
    • F16F—SPRINGS; SHOCK-ABSORBERS; MEANS FOR DAMPING VIBRATION
    • F16F9/00—Springs, vibration-dampers, shock-absorbers, or similarly-constructed movement-dampers using a fluid or the equivalent as damping medium
    • F16F9/32—Details
    • F16F9/44—Means on or in the damper for manual or non-automatic adjustment; such means combined with temperature correction
    • F16F9/46—Means on or in the damper for manual or non-automatic adjustment; such means combined with temperature correction allowing control from a distance, i.e. location of means for control input being remote from site of valves, e.g. on damper external wall
    • F16F9/466—Throttling control, i.e. regulation of flow passage geometry
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B60—VEHICLES IN GENERAL
    • B60G—VEHICLE SUSPENSION ARRANGEMENTS
    • B60G2400/00—Indexing codes relating to detected, measured or calculated conditions or factors
    • B60G2400/20—Speed
    • B60G2400/202—Piston speed; Relative velocity between vehicle body and wheel
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B60—VEHICLES IN GENERAL
    • B60G—VEHICLE SUSPENSION ARRANGEMENTS
    • B60G2401/00—Indexing codes relating to the type of sensors based on the principle of their operation
    • B60G2401/10—Piezoelectric elements
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B60—VEHICLES IN GENERAL
    • B60G—VEHICLE SUSPENSION ARRANGEMENTS
    • B60G2500/00—Indexing codes relating to the regulated action or device
    • B60G2500/10—Damping action or damper
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B60—VEHICLES IN GENERAL
    • B60G—VEHICLE SUSPENSION ARRANGEMENTS
    • B60G2600/00—Indexing codes relating to particular elements, systems or processes used on suspension systems or suspension control systems
    • B60G2600/02—Retarders, delaying means, dead zones, threshold values, cut-off frequency, timer interruption
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B60—VEHICLES IN GENERAL
    • B60G—VEHICLE SUSPENSION ARRANGEMENTS
    • B60G2600/00—Indexing codes relating to particular elements, systems or processes used on suspension systems or suspension control systems
    • B60G2600/22—Magnetic elements
    • B60G2600/26—Electromagnets; Solenoids

Definitions

  • the present invention relates to a shock absorber, and more particularly to a shock absorber having a mechani­cal structure for adjusting damping forces to be generated by the shock absorber.
  • One known shock absorber with adjustable damping force comprises a cylinder, a rod slidably inserted in the cylinder, and a piston mounted on an inner end of the rod and slidably fitted in the cylinder.
  • the piston divides the interior space of the cylinder into first and second fluid chambers.
  • the first and second fluid chambers are connected to each other by a fluid passage whose cross-sectional area can be varied by an actuator operable by an electric signal, thus adjusting damping forces to be generated by the shock absorber.
  • Shock absorbers are generally designed such that it produces higher damping forces when they are expanded than when they are contracted. Therefore, when damping forces are changed in an expansion stroke, large impact forces are produced which makes riding comfort poor. It is preferable that damping forces be changed when the speed at which the shock absorber is expanded or contracted is zero, i.e., when the damping forces are zero. It is more preferable that damping forces be changed the instant the expansion stroke changes to the contraction stroke and when damping forces are zero and the speed of expansion or contraction is zero, or immediately after the expansion stroke changes to the contraction stroke, i.e., the damping forces in the contrac­tion stroke are almost zero.
  • the actuator is controlled by an elec­tronic control unit.
  • the electronic control unit is oper­ated according to various control programs based on a signal from a positional sensor which detects the expansion or con­traction of the shock absorber, so that damping forces can be changed at an accurate time by the electric actuator.
  • the entire system composed of the shock absorber, the elec­tronic control unit, and the positional sensor is however complex in structure.
  • an object of the present invention to provide an adjustable damping force type shock absorber which is capable of changing damping forces at an accurate time with a simple mechanical arrangement.
  • a shock absorber for selectively producing different magnitudes of damping forces, comprising a cylinder, a pis­ton slidably disposed in the cylinder and dividing an inte­rior space of the cylinder into first and second fluid chambers filled with a fluid, means coupled to the piston and defining a main fluid passage providing fluid communica­tion between the first and second fluid chambers at all times and an auxiliary fluid passage providing selective fluid communication between the first and second fluid chambers, and fluid passage control means for opening the auxiliary fluid passage to provide fluid communication between the first and second fluid chambers in response to an external control signal and for closing the auxiliary fluid passage to cut off fluid communication between the first and second fluid chambers when the speed of relative movement of the cylinder and the piston is other than sub­stantially zero.
  • the fluid passage control means comprises an on-off valve including a valve body for selectively opening and closing the auxiliary fluid passage, a spring for normally urging the valve body to close the auxiliary fluid passage, and a fluid chamber for introducing and discharging a fluid in response to movement of the valve body to open and close the auxiliary fluid passage, an actuator responsive to the external control signal for moving the valve body to open the auxiliary fluid passage, and a control valve including a valve body movable in response to a force produced when the cylinder and the piston are moved relatively to each other, and a control fluid passage openable by the valve body of the control valve for bringing the fluid chamber of the on-­off valve into communication with the main fluid passage to cause the on-off valve to close the auxiliary fluid passage when the speed of relative movement of the cylinder and the piston is substantially zero, and closable by the valve body of the control valve for keeping the fluid chamber of the on-off valve sealed in a fluidtight condition to cause the on-off valve to open the auxiliary fluid passage when the speed of relative movement of
  • the shock absorber further includes a check valve for releasing the fluid from the fluid chamber of the on-off valve to allow the on-off valve to open the auxiliary fluid passage regardless of whether the fluid passage is opened or closed by the valve body of the control valve.
  • the control valves has means for bringing the fluid chamber of the on-off valve into communication with the main fluid passage through the control fluid passage when the speed of relative movement of the cylinder and the piston is substantially zero and when the direction of relative move­ment of the cylinder and the piston changes from a shock absorber expansion stroke to a shock absorber contraction stroke.
  • the valve body of the control valve is movable under a frictional force from the cylinder for opening and closing the control fluid passage.
  • the valve body of the control valve comprises a spool valve body having one end subjected to a fluid pres­sure from the first fluid chamber and the other end to a fluid pressure from the second fluid chamber, the spool valve body being movable under the difference between the fluid pressures applied respectively to the ends thereof for opening and closing the control fluid passage.
  • the valve body of the control valve is movable under a fluid pressure in the main fluid passage for opening and closing the control fluid passage.
  • the fluid typically oil
  • the fluid in the cylinder flows between the first and second fluid chambers through the main fluid pas­sage to dampen shocks applied to the shock absorber. Damping forces generated by the shock absorber can be changed by selectively opening and closing the auxiliary fluid passage.
  • the shock absorber When only the main fluid passage is open, the shock absorber operates in a high-damping-force mode.
  • the actuator is operated to shift the on-off valve.
  • the shock absorber When the main and auxiliary fluid pas­sages are open, the shock absorber operates in a low-­damping-force mode.
  • the control valve To close the auxiliary fluid passage, the control valve is axially moved under a force generated when the cylinder and the piston are relatively moved, so that the control fluid passage is opened when the speed of relative movement of the cylinder and the piston is substan­tially zero, thereby releasing the fluid chamber of the on-­off valve from the fluidtight condition, i.e., bringing the fluid chamber of the on-off valve into communication with the main fluid passage.
  • the valve body of the on-off valve is moved under the bias of the spring to close the auxiliary fluid passage while introducing the fluid from main fluid passage through the fluid control passage into the fluid chamber of the on-off valve.
  • the operation mode of the shock absorber now switches from the low-damping-force mode to the high-damping-force mode.
  • the switching from the low-­damping-force mode to the high-damping-force mode is effected when the speed of relative movement of the cylinder and the piston, i.e., the speed of expansion and contraction of the shock absorber, is substantially zero.
  • the operation mode switching is carried out only by a mechanical arrange­ment wherein the valve body of the control valve is axially moved under the force produced when the cylinder and the piston are moved relatively to each other.
  • FIGS. 1 through 4 show a shock absorber with adjustable damping force according to a first embodiment of the present invention.
  • a shock absorber 1 includes a cylinder 3 having a lower end fixed to an axle member 5 and a rod 7 having an upper end fixed to a vehicle body 13 through a bearing 9 and a vibroisolating rubber damper 11.
  • the rod 7 has a lower portion inserted in the cylinder 3 and having on its lower end a housing assembly 15 which com­prises a base member 15A, a joint member 15B partly threaded axially in the base member 15A, and a tubular member 15C extending axially from the joint member 15B.
  • a piston 17 is threaded over and fixed by a nut 16 to the tubular member 15C.
  • the piston 17 is axially slidably fitted in the cylin­der 3 and divides the interior space of the cylinder 3 into a first fluid chamber 19 above the piston 17 and a second fluid chamber 21 below the piston 21.
  • the first and second fluid chambers 19, 21 are held in communication with each other at all times by a main fluid passage 31 defined in the housing assembly 15 and the piston 17, and, additionally, is selectively brought into and out of communication with each other by an auxiliary fluid passage 41.
  • the main fluid pas­sage 31 comprises a passageway 33 defined between the cylin­der 3 and the housing assembly 15, a passageway 35 defined between an end surface 15a of the housing assembly 15 and the piston 17, and passageways 37 defined as restrictions in the piston 17.
  • the auxiliary fluid passage 41 comprises four passageways 43 defined in the base member 15A in commu­nication with the passageway 33 and extending radially out­wardly from the central axis of the base member 15A, a passageway 44 which can selectively be connected to and dis­connected from the passageways 43 by a poppet valve (on-off valve) 51, four passageways 45 connected to the passageway 44 and extending axially in the joint member 15B, four pas­sageways 47 having radially outer ends connected respec­tively to the passageways 45 and radially inner ends joined together, and a passageway 48 connected to the joined ends of the passageways 47 and extending axially through the tubular member 15C.
  • the auxiliary fluid passage 41 inter­connects the first and second fluid chambers 19, 21 in bypa­ssing relation to the passageways 37.
  • the valve body 53 of the poppet valve 53 which is disposed in the passageway 44 serves to change damping forces to be generated by the shock absorber 1.
  • the valve body 53 selectively opens and closes the auxiliary fluid passage 41 under the control of an actu­ator 61, a slide valve (on-off valve) 71, and a check valve 81.
  • the actuator 61 comprises a laminated piezoelectric element 63 housed in a chamber 62 defined in the base member 15A, a piston 63 held against one end of the piezoelectric element 63, a Belleville spring 65 disposed in the chamber 62 for normally urging the piston 64 against the piezoelectric element 63, a noncompressible oil 66 filled in a fluidtight manner in a chamber defined between the bottom of the chamber 62 and the piston 64, and a plunger 67 axially slidable under the pressure of the oil 66.
  • the actuator 61 is operable by an electric signal sup­plied from an electronic control unit (not shown) which operates based on a detected signal from a road surface sen­sor (not shown) or the like.
  • an electric signal is applied to the piezoelectric element 63 through a lead wire 68, the piezoelectric member 63 is expanded to cause the piston 64 and the oil 66 to move the plunger 67 in the direction indicated by the arrow a .
  • the piezoelectric element 63 is con­tracted to allow the spring 65 to return the plunger 67 to its original position through the oil 66.
  • the valve body 53 of the poppet valve 51 is sli­dably fitted in a hole 54 defined axially in the joint member 15B.
  • the valve body 53 is normally urged in a direc­tion to close the auxiliary fluid passage 41 by means of a spring 56 disposed between the bottom of a bottomed hole 55 defined in the valve body 53 and the end of the hole 54.
  • the valve body 53 has a central projection 53a on its outer end in axially confronting relation to the plunger 67.
  • the slide valve 71 comprises an annular valve body 73 axially slidably fitted in an annular groove 72 defined in the outer peripheral surface of the joint member 15B and having radially inwardly extending guide teeth 73a fitted respectively in guide slots 15b defined in the joint member 15B, four retainers 74 projecting radially outwardly from the outer peripheral surface of the annular valve body 73 and angularly spaced at equal intervals of 90°, with the passageway 33 being defined between the retainers 74, con­tact members 75 retained respectively by the retainers 74 and having outer peripheral surfaces held against the inner peripheral surface of the cylinder 3, and Belleville springs 76 disposed in the respective retainers 74 for normally urg­ing the contact members 75 toward the inner peripheral sur­face of the cylinder 3.
  • each of the contact members 75 should preferably be made of a material having a large coefficient of friction or be roughened to provide large forces of friction between itself and the inner peripheral surface of the cylinder 3, or be of a semicylindrical shape complementary to the inner periph­eral surface of the cylinder 3 to provide a large area of contact between itself and the inner peripheral surface of the cylinder 3.
  • the control fluid passage 91 has passageways 92, 93 connected to the fluid chamber 57 in the poppet valve 51, and a passageway 94 defined in a portion (in the upper side shown in FIG. 2) of the valve body 73.
  • the annular valve body 73 is movable in the directions indicated by the arrows a , b between stoppers 72a, 72b at the axial ends of the annular groove 72, so that the annular valve body 73 selec­tively connects and disconnects the passageways 93, 94 to bring the fluid chamber 57 into and out of communication with the main fluid passage 31.
  • the check valve 81 is disposed in a passageway 95 defined in the joint member 15B and communicating with the fluid chamber 57.
  • the check valve 81 can discharge the oil from the fluid chamber 57 into the main fluid passage 31 through the passageways 92, 95, a passageway 96 joined to the passageway 95, and a passageway 97 defined in the valve body 73 of the slide valve 71.
  • the check valve 81 however prevents an oil flow in the opposite direction.
  • the check valve 81 is of a general construction comprising a ball 83 and a spring 85 for biasing the ball 83.
  • the shock absorber 1 is in a neutral position as shown in FIG. 2 with the poppet valve 51 closing the auxiliary fluid passage 41.
  • the valve body 73 moves in unison with the cylinder 3 due to the friction between the outer surfaces of the contact members 75 and the inner peripheral surface of the cylinder 3.
  • the valve body 73 is stopped when it engages the stopper 72a on one end of the annular groove 72. Since the passageway 94 in the valve body 73 is disconnected from the passageway 93 at this time, the fluid chamber 57 of the poppet valve 51 is held out of communication with, i.e., closed with respect to, the main fluid passage 31.
  • the shock absorber 1 operates to produce high damping forces.
  • the piezoelectric element 63 is expanded to cause the piston 64 and the oil 66 to move the plunger 67 in the direction indicated by the arrow c (FIG. 6).
  • the distal end of the plunger 67 engages the projection 53a of the pop­pet valve 51, and pushes the valve body 53 against the bias of the spring 56.
  • the valve body 53 opens the auxiliary fluid passage 44 while discharg­ing the oil from the fluid chamber 57 into the main fluid passage 31 through the passageways 92, 95, 96, 97 and the check valve 81.
  • the check valve 81 will be closed at the same time that the opening movement of the poppet valve 51 is completed.
  • the oil in the first fluid chamber 19 there­fore flows through the main fluid passage 31 and also the auxiliary fluid passage 41 into the second fluid chamber 21. Accordingly, the shock absorber 1 operates to produce low damping forces.
  • the valve body 73 remains held against the stopper 72a, and hence the poppet valve 51 remains open as shown in FIG. 6.
  • the shock absorber 1 is contracted from the expanded condition and the cylinder 3 is moved in the direc­ tion indicated by the arrow b as shown in FIG. 8.
  • the valve body 73 is moved with the cylinder 3 as indicated by the arrow b due to the friction between the inner peripheral surface of the cylinder 3 and the outer surfaces of the contact members 75.
  • the fluid passages 94, 93 are brought into radial registry with each other, the fluid chamber 57 communicates with the main fluid passage 31 through the control fluid passage 91. Therefore, the fluid chamber 57 is released of the fluidtight condition, and the valve body 53 of the poppet valve 51 is moved in the direction indicated by the arrow b under the resiliency of the spring 56.
  • the poppet valve 51 now closes the auxiliary fluid passage 41 while the oil is being intro­duced from the main fluid passage 31 through the control fluid passage 91 into the fluid chamber 57.
  • the shock absorber 1 is automatically switched from the low-­damping-force mode to the high-damping-force mode.
  • the valve body 73 slides with the cylinder 3 until it engages the stopper 72b.
  • the fluid chamber 57 is now put out of communication with the main fluid passage 31, but the shock absorber 1 keeps on producing high damping forces unless the poppet valve 51 is opened.
  • the shock absorber 1 starts to be con­tracted at a time t0 from the neutral position (FIG. 1) to produce the high damping force. Thereafter, at a time t1, the actuator 61 is operated to enable the shock absorber 1 to produce the low damping force.
  • the electric control sig­nal is continuously applied to the actuator 61 until a time t2. Therefore, the poppet valve 51 remains open and the shock absorber 1 remains in the low-damping-force mode.
  • the electric control signal applied to the actuator 61 is discontinued.
  • the low damping force is maintained until a time t3 at which time the shock absorber 1 switches from the expanded condition to the con­tracted condition and the switching speed is almost zero.
  • the poppet valve 51 is closed and the shock absorber 1 operates in the high-­damping-force mode.
  • the operation mode of the shock absorber 1 can be changed from the high-damping-force mode to the low-damping-­force mode at any time by applying the control signal to the actuator 61. However, the operation mode is changed from the low-damping-force mode to the high-damping-force mode only when the shock absorber 1 switches from the expanded condition to the contracted condition or vice versa and the switching speed is zero to operate the slide valve 71 and the poppet valve 51.
  • the shock absorber 1 is usually designed such that the higher the speed of movement of the piston 17, the greater the difference between the high and low damping forces produced by the shock absorber 1. Therefore, if the damping-force modes were changed when the piston speed is high, the shock absorber 1 would produce impact forces impairing riding comfort. According to the aforesaid embodiment, however, since the damping-force modes are changed when the damping forces are zero, i.e., when the speed of expansion and contraction of the shock absorber 1 is almost zero, produced damping forces do not vary greatly, and any impact or impulsive forces produced are of a low level which does not make riding comfort poor.
  • the damping-force modes are changed not by an elec­tric arrangement, but by the mechanical arrangement includ­ing the slide valve 71 and the poppet valve 51.
  • the employed mechanical construction is simple and highly relia­ble in operation.
  • the four retainers 74 and the four contact members 75 are provided at equal angular intervals of 90° in the slide valve 71, three or six retainers and three or six contact members may be employed in view of slidability and balancing of the valve body 73.
  • FIGS. 11 through 14 illustrate an adjustable damp­ing force type shock absorber according to a second embodi­ment of the present invention.
  • the shock absorber of the second embodiment differs from the shock absorber of the first embodiment except that a spool valve 101 is employed in place of the slide valve 71.
  • the spool valve 101 is incorporated in the joint member 15B of the housing assembly 15.
  • the spool valve 101 comprises a spool valve body 103 slidably fitted in a hole 102 defined radially in the joint member 15B and having a substantially central annular groove 103a defined in the outer peripheral surface thereof, and a pair of springs 104a, 104b disposed in the hole 102 and acting on the respective opposite ends of the spool valve body 103 for normally urging the spool valve body 103 into a neutral position.
  • the hole 102 has a port in one end thereof which communicates with the first fluid chamber (see FIG. 4) through a passageway 105 defined in the joint member 15B and the main fluid passage 31.
  • the hole 102 also has a port in the other end which communicates with the second fluid cham­ber 21 through a passageway 106 defined in the joint member 15B.
  • the hole 102 also has central ports, one communicating with the fluid chamber 57 through a passageway 113 defined in the joint member 15B and the other with the passageway 35 through a passageway 115 defined in the joint member 15B.
  • the passageways 113, 115 jointly serve as a control fluid passage 111.
  • a check valve 81A has an upstream end connected to the fluid chamber 57 through a passageway 116 defined in the joint member 15B and a passageway 117 defined in a side wall of the valve body 53 of the poppet valve 51, and a down­stream end connected to the main fluid passage 31 through a passageway 118 in the joint member 15B.
  • the passageway 117 may be directly connected to the passageway 113 as with the first embodiment.
  • the shock absorber according to the second embodi­ment operates as follows: When the shock absorber is not expanded as shown in FIG. 11, the spool valve body 103 is in the neutral position as shown because the oil pressure applied from the first fluid chamber 19 through the passage­way 105 to one end of the spool valve body 103 is equal to the oil pressure applied from the second fluid chamber 21 through the passageway 106 to the other end of the spool valve body 103, and also because the spring forces of the springs 104a, 104b are equal to each other. Therefore, the fluid chamber 57 communicates with the main fluid passage 31 through the passageway 113, the annular groove 103a, and the passageway 115.
  • the operation mode of the shock absorber switches from the high-damping-force mode to the low-damping-force mode in the same manner as described above with reference to the first embodiment.
  • the shock absorber When the shock absorber is then expanded, the oil pressure in the first fluid chamber 19 becomes higher than the oil pressure in the second fluid chamber 21. Therefore, the oil pressure applied from the first fluid chamber 19 to one end of the spool valve body 103 through the passageway 105 becomes higher than the oil pressure applied from the second fluid chamber 21 to the other end of the spool valve body 103 through the passageway 106.
  • the spool valve body 103 is now moved in the direction indicated by the arrow f (FIG. 11) against the bias of the spring 104b. As a consequence, the spool valve body 103 brings the passageways out of communication with each other, whereupon the fluid chamber 57 is disconnected from the main fluid passage 31.
  • the shock absorber When the shock absorber is contracted, the oil pressures applied to the ends of the spool valve body 103 are reversed in magnitude, and hence the spool valve body 103 is moved in the direction of the arrow e against the resiliency of the spring 104a.
  • the instant the annular groove 103a allows communication between the passageways 113, 115, the fluid chamber 57 is connected to the main fluid passage 31.
  • the fluid chamber 57 is now released of the fluidtight condition, allowing the valve body 53 to close the auxiliary fluid passage 41 under the force of the spring 56. Therefore, the damping-force mode of the shock absorber is automatically switched from the low-damping-­force mode to the high-damping-force mode.
  • the shock absorber according to the third embodi­ment differs from the shock absorber according to the first embodiment in that it employs a slide valve 121 of a different structure.
  • the housing assembly 15 includes a joint member 15E threaded over a base member 15D.
  • the joint member 15E has an outer annular groove 122 defined in the outer peripheral surface thereof on the righthand side (as shown) of the aux­iliary fluid passage 41, and an inner annular groove 123 defined centrally in the outer annular groove 122.
  • the slide valve 151 includes an axially slidable annular valve body 124 disposed in the inner annular groove 123 and held out of contact with the inner peripheral surface of the cyl­inder 3. Springs 125a, 125b are supported on the opposite end surfaces of the outer annular groove 122 for acting on the opposite axial ends of the annular valve body 124.
  • the valve body 124 has a passageway 135 defined therein.
  • the passageway 135 and another passageway 133 defined in the joint member 15E jointly serve as control fluid passage 131.
  • the valve body 124 is kept in a neutral position in FIG. 15 because the oil pressure applied from the first fluid chamber 19 through the main fluid passage 31 to one axial end of the valve body 124 is equal to the oil pressure applied from the second fluid chamber 21 through the main fluid passage 31 to the other axial end of the valve body 124, and also because the springs 125a, 125b have equal spring forces.
  • the shock absorber When the shock absorber is expanded from the neu­tral position, the oil in the first fluid chamber 19 flows through the main fluid passage 31 into the second fluid chamber 21. At this time, the valve body 124 moves in the same direction as the oil flow under the pressure of the oil flowing through the main fluid passage 31. As a result, the passageway 135 is shifted out of registry with the passage­way 133, and the fluid chamber 57 of the poppet valve 51 is brought out of communication with the main fluid chamber 31.
  • the valve body 124 of the slide valve 121 axially slides under the dynamic pressure of the oil flowing through the main fluid passage 31 to close and open the control fluid passage 131.
  • the poppet valve 51 is closed, and the operation mode switches from the low-damping-force mode to the high-damping-force mode.
  • the poppet valve 51 may be opened to switch the operation mode from the high-damping-force mode to the low-­damping-force mode at any time by operating the actuator 61.
  • the slide valve 121 is positioned on the righthand side of the auxiliary fluid passage 41, i.e., on the righthand side of a point where the auxiliary fluid pas­sage 41 is branched from the main fluid passage 31, the slide valve 121 may be positioned on the lefthand side of the auxiliary fluid passage 41, i.e., at a position closer to the second fluid chamber 21.
  • the absolute value of the dynamic pressure of the fluid applied to the slide valve 124 is lower than the pressure in the third embodiment.
  • the slide valve body can still slide axially on the joint member 15E, making it pos­sible to change damping forces.
  • the check valve is employed to release the oil from the fluid chamber 57 for opening the poppet valve 51.
  • another means may be employed to allow the poppet valve 51 to be opened, as shown in FIG. 18.
  • the restriction hole 200 may be provided in addi­tion to the check valve employed in each of the first through three embodiments. More specifically, if the shock absorber is expanded and contracted at a very high speed, then a small amount of oil may flow out of the fluid chamber through the gap around the valve body 53, letting the poppet valve 51 be open unexpectedly. With the restriction hole 200 provided, however, the pressure in the fluid chamber 57 is prevented from varying undesirably, and the poppet valve 51 can be operated stably.
  • the poppet valve 51 when the shock absorber is expanded and contracted at a high speed, i.e., when damping forces are large, the poppet valve 51 is opened slowly to reduce abrupt changes in damping forces at the time the operation mode switches from the high-damping-force mode to the low-damping-force mode.
  • the poppet valve 51 is opened quickly to provide good damping force controlling characteristics.
  • the laminated piezoelectric element is employed as the actuator for open­ing the poppet valve.
  • a solenoid-operated actuator 141 may be employed which includes a solenoid coil 143 and a plunger 144 extending axially through the solenoid coil 143.
  • the solenoid coil 143 When the solenoid coil 143 is energized, the plunger 144 is axially moved against the bias of a spring 146 to open the poppet valve 51.
  • a drive unit such as a motor or the like may be employed to move the plunger.
  • the poppet valve 51 for opening and closing the auxiliary fluid passage 41 in the above embodiments may be replaced with a spool valve.
  • the operation mode of the shock absorber is switched from the low-damping-force mode to the high-damping-force mode by a mechanical arrange­ment which employs a hydraulic pressure circuit that util­izes a force produced when the cylinder and the piston are relatively moved, but not by the conventional complex elec­tric arrangement.
  • the operation mode of the shock absorber is switched from the low-damping-force mode to the high-­damping-force mode when produced damping forces are zero or almost zero, any shocks or impact forces produced by the shock absorber are small, and riding comfort is not impaired.

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  • Engineering & Computer Science (AREA)
  • General Engineering & Computer Science (AREA)
  • Mechanical Engineering (AREA)
  • Fluid-Damping Devices (AREA)
  • Vehicle Body Suspensions (AREA)
EP89112472A 1988-07-08 1989-07-07 Amortisseur de chocs à force d'amortissement réglable Expired - Lifetime EP0350061B1 (fr)

Applications Claiming Priority (2)

Application Number Priority Date Filing Date Title
JP63171669A JPH0221043A (ja) 1988-07-08 1988-07-08 減衰力可変ショックアブソーバ
JP171669/88 1988-07-08

Publications (3)

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EP0350061A2 true EP0350061A2 (fr) 1990-01-10
EP0350061A3 EP0350061A3 (fr) 1991-02-27
EP0350061B1 EP0350061B1 (fr) 1994-11-23

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EP89112472A Expired - Lifetime EP0350061B1 (fr) 1988-07-08 1989-07-07 Amortisseur de chocs à force d'amortissement réglable

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Country Link
US (1) US5078239A (fr)
EP (1) EP0350061B1 (fr)
JP (1) JPH0221043A (fr)
DE (1) DE68919445T2 (fr)

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EP0485647A1 (fr) * 1989-02-14 1992-05-20 H. Neil Paton Amortisseur à friction actionné hydrauliquement
ES2064201A2 (es) * 1991-09-20 1995-01-16 Boge Ag Amortiguador de vibraciones para vehiculos automoviles.
EP2309149A3 (fr) * 2009-10-06 2014-05-28 Audi AG Véhicule automobile doté d'un dispositif d'amortissement, dispositif d'amortissement et composant pour dispositif d'amortissement

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US5271485A (en) * 1992-09-23 1993-12-21 Predator Systems Inc. Hydraulic damper
US5737040A (en) 1994-07-12 1998-04-07 Dai Nippon Printing Co., Ltd. Liquid crystal display apparatus and liquid crystal projection display apparatus which employ hologram color filter
US5921544A (en) * 1995-11-30 1999-07-13 Xerox Corporation Acquisition levitation transport device
DE102010062264B4 (de) * 2010-12-01 2012-08-23 Zf Friedrichshafen Ag Verstellbare Dämpfventileinrichtung für einen Schwingungsdämpfer
US8991569B1 (en) * 2011-11-16 2015-03-31 Armorworks Enterprises LLC Strut with adaptive energy attenuation
JP5918587B2 (ja) * 2012-03-28 2016-05-18 Ｋｙｂ株式会社 緩衝器
JP6582055B2 (ja) * 2015-10-22 2019-09-25 京セラ株式会社 路面状態判定装置、撮像装置、撮像システムおよび路面状態判定方法
WO2019049844A1 (fr) * 2017-09-05 2019-03-14 日立オートモティブシステムズ株式会社 Amortisseur
EP3805597A4 (fr) * 2018-06-01 2022-04-06 Showa Corporation Dispositif de commande de passage d'écoulement et dispositif d'ajustement de hauteur de véhicule
KR20200113807A (ko) * 2019-03-26 2020-10-07 주식회사 만도 감쇠력 가변식 쇽업소버
CN111536186B (zh) * 2019-05-06 2021-07-23 北京京西重工有限公司 阻尼器组件和用于阻尼器组件的活塞
DE102020209101A1 (de) * 2020-07-21 2022-01-27 Zf Friedrichshafen Ag Drosselstelle mit einem sich im Durchmesser ändernden Ventilkörper

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JPS59147134A (ja) * 1983-02-09 1984-08-23 Nissan Motor Co Ltd 減衰力可変式シヨツクアブソ−バ
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Cited By (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
EP0485647A1 (fr) * 1989-02-14 1992-05-20 H. Neil Paton Amortisseur à friction actionné hydrauliquement
ES2064201A2 (es) * 1991-09-20 1995-01-16 Boge Ag Amortiguador de vibraciones para vehiculos automoviles.
EP2309149A3 (fr) * 2009-10-06 2014-05-28 Audi AG Véhicule automobile doté d'un dispositif d'amortissement, dispositif d'amortissement et composant pour dispositif d'amortissement

Also Published As

Publication number Publication date
EP0350061A3 (fr) 1991-02-27
DE68919445T2 (de) 1995-07-20
EP0350061B1 (fr) 1994-11-23
US5078239A (en) 1992-01-07
DE68919445D1 (de) 1995-01-05
JPH0221043A (ja) 1990-01-24

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